It wants full sun and free draining soil, and it is at its best in dry, breezy positions including coastal ones. Heat, wind and drought are no trouble once established, and it takes light to moderate frost. Growth runs 30 to 60 centimetres a year, so plan on trimming a few times a season.
Pairs of balls flank entries, doorways and steps, and single plants sit well in pots on a terrace or repeated through a border for rhythm. The silver reads strongly against dark green hedging and against grey stone. It is a low water way of getting formal structure into a garden.
Frequently Asked Questions
About Helichrysum petiolare Ball
What is Helichrysum petiolare?
It is a soft wooded evergreen shrub from southern Africa, grown almost entirely for its foliage. The common name liquorice plant comes from the faint scent of the crushed leaves. Left alone it sprawls and trails, which is why it often appears in hanging baskets, but it clips readily into a formal ball.
How big does the topiary ball get?
As a maintained topiary it is normally held between 40 and 60 centimetres across, and regular trimming keeps it there indefinitely. Left unclipped the plant sprawls to a metre or more wide and loses the shape entirely. The size you buy is close to the size you keep, given a few trims a year.
Does it need sun or shade?
Full sun. The silver grey foliage is at its brightest in strong light, and the growth stays tight and compact. In shade the stems stretch, the ball opens up and the colour dulls towards green. It will accept a little afternoon shade in very hot inland areas, but a sunny open spot is best.
Can it be grown in a pot?
Yes, and containers suit it particularly well. Use a free draining mix, a pot with real drainage holes, and let the surface dry between waterings, since the roots rot in constantly wet mix. Feed lightly in spring. Potted plants dry out faster in summer, so check them through heatwaves.
Is it suitable for coastal gardens?
Yes. It handles salt laden wind, sandy soil and reflected heat, which makes it one of the more reliable formal shapes for a coastal garden. Drainage and air movement matter more than shelter. Rinse salt off the foliage occasionally in very exposed positions to keep the silver looking clean.
Does it flower?
Small cream to pale yellow flower clusters appear in summer, roughly December to February. They are modest, and many gardeners clip them off to keep the ball crisp and push energy back into the foliage. The plant is grown for its silver leaves, so flowering is a minor event either way.
How do I trim and care for the topiary ball?
Trim lightly every six to eight weeks through the growing season, taking small amounts often rather than cutting hard, since bare old wood reshoots slowly. Water deeply but let the soil dry between times. Feed once in spring with a slow release fertiliser. Renovate a leggy plant in early spring, not in autumn.
